Electrical equipment, such as power transmission lines, insulators, surge arrestors, switchgear and transformers (e.g., operating at voltages in excess of 1 kV and particularly in excess of 10 kV, such voltages hereinafter being referred to as “high voltage”), often have parts thereof or parts associated therewith that are not insulated from the surrounding air. Thus, an exposed portion of such equipment can be at high voltage and be longitudinally separated from another portion at low voltage, for example at earth potential. The exposed high voltage portion may be physically supported by an insulator, for example when an overhead power line is mounted on an insulator that spaces it from a supporting tower that is itself at earth potential, or for example when a high voltage cable is terminated at a bushing or switchgear whose metal housing is at earth potential. In such instances outdoors, larger wildlife such as birds with large wingspans may be big enough to form a direct bridge (i.e., an electrical short circuit) between the high voltage equipment and earth potential, with serious, usually fatal, consequences for themselves and often with serious consequences for the electrical equipment and the supply of electrical power—usually at least a fuse is actuated or a circuit breaker triggered such that the power supply is interrupted.
Birds nesting on distribution power poles have in particular become quite a problem for utilities. Large birds, like ospreys and eagles, can create nests so large that they cause flash-overs when the nests touch phase to phase or phase to ground. Repair of the line, customer power outages, pole fires and bird mortality are all major concerns.